Here's one from a recent fave "The Secret of Lost Things" by Sheridan Hay...

I was born before the story starts, before I dreamed of such a place as the Arcade, before I imagined men like Walter Geist existed outside of fables, outside of fairy tales.

I reckon the most amusing first sentence is in PG Wodehouse's "The Luck of the Bodkins", published in the 1930s.

"Into the face of the young man who sat on the terrace of the Hotel Magnifique at Cannes there had crept

a look of furtive shame, the shifty, hangdog look which announces that an Englishman is about to talk French".